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Related papers: U-Spin Tests of the Standard Model and New Physics

200 papers

New physics (NP) in charmless strangeness-changing $B$ and $B_s$ decays, which are dominated by the $b \to s$ penguin amplitudes, can either preserve isospin or change it by one unit. A general formalism is presented studying pairs of…

High Energy Physics - Phenomenology · Physics 2008-11-26 Michael Gronau , Jonathan L. Rosner

The penguin loop-suppressed $B\to\phi K$ decays are highly sensitive to contributions of hypothetical heavy new particles. Particularly interesting probes for testing the Standard Model and revealing such phenomena are provided by CP…

High Energy Physics - Phenomenology · Physics 2026-03-16 Robert Fleischer , Jelle Groot , K. Keri Vos

For about twenty years, $B\to\pi K$ decays are in the focus of $B$-decay studies. We show that a correlation between the CP asymmetries of $B^0_d\to\pi^0K_{\rm S}$ reveals a tension with the Standard Model. Should it be due to New Physics,…

High Energy Physics - Phenomenology · Physics 2018-05-23 Robert Fleischer , Ruben Jaarsma , Eleftheria Malami , K. Keri Vos

If physics beyond the standard model is present in B decays, experimental measurements seem to suggest that it principally affects those processes with significant b->s penguin amplitudes. It was recently argued that, in general, such…

High Energy Physics - Phenomenology · Physics 2009-11-10 David London , Joaquim Matias , Javier Virto

We argue that the observation of a sizable direct CP asymmetry A_{CP} in the inclusive decays B -> X_s gamma would be a clean signal of New Physics. In the Standard Model, A_{CP} can be calculated reliably and is found to be below 1% in…

High Energy Physics - Phenomenology · Physics 2016-08-25 A. L. Kagan , M. Neubert

Recently, we developed a strategy to analyse the B -> pi pi,pi K data. We found that the B -> pi pi measurements can be accommodated in the Standard Model (SM) through large non-factorizable effects. On the other hand, our analysis of the…

High Energy Physics - Phenomenology · Physics 2007-05-23 Andrzej J. Buras , Robert Fleischer , Stefan Recksiegel , Felix Schwab

We consider several hints for new physics involving CP-asymmetries in B-decays and interpret them in terms of generic contributions to effective Wilson coefficients. The effects we focus on are: the differences in the fitted value of sin(2…

High Energy Physics - Phenomenology · Physics 2009-08-22 E. Lunghi , A. Soni

The measurements of B -> pi K decays have been in disagreement with the predictions of the Standard Model (SM) for some time. In this paper, we perform an update of this puzzle using the latest (2008) data. We find that the situation has…

High Energy Physics - Phenomenology · Physics 2014-11-18 Seungwon Baek , Cheng-Wei Chiang , David London

The non-leptonic $D^0\to K^- K^+$ and $D^0\to \pi^-\pi^+$ decays are powerful probes of the Standard Model and are related to each other through the $U$-spin symmetry of the strong interaction. Using lattice QCD inputs we calculate the…

High Energy Physics - Phenomenology · Physics 2025-12-12 Robert Fleischer , Maria Laura Piscopo , K. Keri Vos , B. Yağmur Zubaroğlu

If new physics (NP) is present in B -> pi pi decays, it can affect the isospin I=2 or I=0 channels. In this paper, we discuss various methods for detecting and measuring this NP. The techniques have increasing amounts of theoretical…

High Energy Physics - Phenomenology · Physics 2014-11-18 Seungwon Baek , F. J. Botella , David London , Joao P. Silva

Precision measurements of branching fractions and CP asymmetries in non-leptonic b -> s decays reveal certain "puzzles" when compared with Standard Model expectations based on a global fit of the CKM triangle and general theoretical…

High Energy Physics - Phenomenology · Physics 2009-01-06 Thorsten Feldmann , Martin Jung , Thomas Mannel

The recently observed direct CP violation in $B_d \to K^+ \pi^-$ has raised suggestions of possible new physics. A robust test of the standard model vs. new physics is its prediction of equal direct CP violation in $B_s \to K^- \pi^+$…

High Energy Physics - Phenomenology · Physics 2010-04-05 Harry J. Lipkin

Recent LHCb data shows that the direct CP asymmetries of the decay modes $D^0\rightarrow \pi^+\pi^-$ and $D^0\rightarrow K^+K^-$ have the same sign, violating an improved $U$-spin limit sum rule in an unexpected way at $2.1\sigma$. From the…

High Energy Physics - Phenomenology · Physics 2023-04-12 Stefan Schacht

Recent experiments suggest that certain data of $B \to \pi\pi,\pi K$ decays are inconsistent with the standard model expectations. We try to explain the discrepancies with R-parity violating suppersymmetry. By employing the QCD…

High Energy Physics - Phenomenology · Physics 2014-11-18 Ya-Dong Yang , Rumin Wang , G. R. Lu

In this talk, I review the various measurements that have been made over the years of CP-violating observables in $B$ decays. These include indirect CP asymmetries, direct CP asymmetries, and triple products. All are discussed in the…

High Energy Physics - Phenomenology · Physics 2020-07-14 David London

There are strong similarities between charge-parity (CP) violating observables in hadronic $B$ decays (in particular $\Delta A^-_{\rm CP}$ in $B\to K\pi$) and direct CP violation in Kaon decays ($\epsilon^\prime$): All these observables are…

High Energy Physics - Phenomenology · Physics 2020-02-05 Andreas Crivellin , Christian Gross , Stefan Pokorski , Leonardo Vernazza

The rare decay B -> K* (-> K pi) mu+ mu- is regarded as one of the crucial channels for B physics as the polarization of the K* allows a precise angular reconstruction resulting in many observables that offer new important tests of the…

High Energy Physics - Phenomenology · Physics 2011-05-23 Wolfgang Altmannshofer , Patricia Ball , Aoife Bharucha , Andrzej J. Buras , David M. Straub , Michael Wick

Exploring correlations between the CP asymmetries of $B^0_d\to\pi^0K_{\rm S}$ following from an isospin relation, we uncover new tensions with the Standard Model in data for neutral $B\to\pi K$ decays. Should this intriguing picture…

High Energy Physics - Phenomenology · Physics 2018-10-17 Robert Fleischer , Ruben Jaarsma , K. Keri Vos

In certain new physics (NP) models, such as the Littlest Higgs model with T-parity, a strict correlation between the K_L -> pi0 nu anti-nu and K+ -> pi+ nu anti-nu branching ratios has been observed, allowing essentially only for two…

High Energy Physics - Phenomenology · Physics 2010-05-12 Monika Blanke

We present a model independent analysis of new-physics contributions to the decays K^+ \to \pi^+ \nu \bar \nu and K_L \to \pi^0 \nu \bar \nu. We parameterize the effects of new physics in these decays by two parameters: r_K and \theta_K,…

High Energy Physics - Phenomenology · Physics 2009-10-30 A. J. Buras , A. Romanino , L. Silvestrini